The Trump campaign has launched a new attack against Hillary Clinton: She’s too frail and feeble to be president. In a speech last week, Trump said she “lacks the mental and physical stamina to take on ISIS, and all the many adversaries we face.” Since then, Trump surrogates like Rudy Giuliani have spread the conspiracy by telling voters to google Clinton’s many ailments.

Clinton, Giuliani said, is “tired” and “looks sick.” What could possibly be wrong with her? Surely something that necessitates she be propped up at all times on any number of comfortable cushions. Surely something sinister that would prevent her from taking office.

On Tuesday, Stephen Colbert finally figured it out. “I don’t know why they keep saying things like frail, or weak, or low energy,” he said during a segment on The Late Show*. “You’re just tiptoeing around the medical condition that you’re really upset about, one that she has that no other president in history has ever faced: Hillary Clinton has Chronic No-Penis.”

“It’s congenital,” he went on. “Every woman in her family has had the same thing.” And, judging by the commentary that continues to be published as Clinton makes history, there’s no cure.

*An earlier version of this post incorrectly referred to Stephen Colbert’s show as The Tonight Show.